With the ->set_acl inode operation we can implement the Posix ACL
xattr handlers in generic code instead of duplicating them all
over the tree.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
---
fs/xattr_acl.c | 102 +++++++++++++++++++++++++++++++++++++++
include/linux/posix_acl_xattr.h | 3 ++
2 files changed, 105 insertions(+)
diff --git a/fs/xattr_acl.c b/fs/xattr_acl.c
index 9fbea87..536015e 100644
--- a/fs/xattr_acl.c
+++ b/fs/xattr_acl.c
@@ -10,6 +10,7 @@
#include <linux/posix_acl_xattr.h>
#include <linux/gfp.h>
#include <linux/user_namespace.h>
+#include <linux/xattr.h>
/*
* Fix up the uids and gids in posix acl extended attributes in place.
@@ -178,3 +179,104 @@ posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
return real_size;
}
EXPORT_SYMBOL (posix_acl_to_xattr);
+
+static int
+posix_acl_xattr_get(struct dentry *dentry, const char *name,
+ void *value, size_t size, int type)
+{
+ struct posix_acl *acl;
+ int error;
+
+ if (!IS_POSIXACL(dentry->d_inode))
+ return -EOPNOTSUPP;
+ if (S_ISLNK(dentry->d_inode->i_mode))
+ return -EOPNOTSUPP;
+
+ acl = get_acl(dentry->d_inode, type);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+
+ error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+ posix_acl_release(acl);
+
+ return error;
+}
+
+static int
+posix_acl_xattr_set(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags, int type)
+{
+ struct inode *inode = dentry->d_inode;
+ struct posix_acl *acl = NULL;
+ int ret;
+
+ if (!IS_POSIXACL(inode))
+ return -EOPNOTSUPP;
+ if (S_ISLNK(inode->i_mode) || !inode->i_op->set_acl)
+ return -EOPNOTSUPP;
+
+ if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
+ return value ? -EACCES : 0;
+ if (!inode_owner_or_capable(inode))
+ return -EPERM;
+
+ if (value) {
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+
+ if (acl) {
+ ret = posix_acl_valid(acl);
+ if (ret)
+ goto out;
+ }
+ }
+
+ ret = inode->i_op->set_acl(inode, acl, type);
+out:
+ posix_acl_release(acl);
+ return ret;
+}
+
+static size_t
+posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
+ const char *name, size_t name_len, int type)
+{
+ const char *xname;
+ size_t size;
+
+ if (!IS_POSIXACL(dentry->d_inode))
+ return -EOPNOTSUPP;
+ if (S_ISLNK(dentry->d_inode->i_mode))
+ return -EOPNOTSUPP;
+
+ if (type == ACL_TYPE_ACCESS)
+ xname = POSIX_ACL_XATTR_ACCESS;
+ else
+ xname = POSIX_ACL_XATTR_DEFAULT;
+
+ size = strlen(xname) + 1;
+ if (list && size <= list_size)
+ memcpy(list, xname, size);
+ return size;
+}
+
+const struct xattr_handler posix_acl_access_xattr_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .flags = ACL_TYPE_ACCESS,
+ .list = posix_acl_xattr_list,
+ .get = posix_acl_xattr_get,
+ .set = posix_acl_xattr_set,
+};
+EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
+
+const struct xattr_handler posix_acl_default_xattr_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .flags = ACL_TYPE_DEFAULT,
+ .list = posix_acl_xattr_list,
+ .get = posix_acl_xattr_get,
+ .set = posix_acl_xattr_set,
+};
+EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
diff --git a/include/linux/posix_acl_xattr.h b/include/linux/posix_acl_xattr.h
index ad93ad0..6f14ee2 100644
--- a/include/linux/posix_acl_xattr.h
+++ b/include/linux/posix_acl_xattr.h
@@ -69,4 +69,7 @@ struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
int posix_acl_to_xattr(struct user_namespace *user_ns,
const struct posix_acl *acl, void *buffer, size_t size);
+extern const struct xattr_handler posix_acl_access_xattr_handler;
+extern const struct xattr_handler posix_acl_default_xattr_handler;
+
#endif /* _POSIX_ACL_XATTR_H */
--
1.7.10.4
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